This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Evaluation of inflammation in the respiratory tract under environmentally controlled conditions will distinguish patients with various types of airway obstruction. It is possible to develop a systematic approach to classify severe asthma in a controlled environment, identify specific causes, and thus focus treatment on the etiology.